Iron deficiency continues to be a common nutritional problem at the present time. Iron deficiency is a major problem in the developing world and affects almost all segments of the population. It is particularly severe in infants and childbearing women. See MacPhail and Bothwell, "Fortification of the Diet as a Strategy for Preventing Iron Deficiency," Acta Paediatric Scand. Supplement, 361: 114 (1989).
Even in industrialized countries, one segment of the population that remains highly vulnerable to iron deficiency is preschool and school-aged children because their requirements for iron for growth often exceed the dietary supply of iron. Iron requirements for adolescents can be increased further by strenuous athletic programs and, in turn, their athletic performance can be impaired by the development of iron deficiency. See Hurrell, "Ferrous Fumarate Fortification Of A Chocolate Drink Powder," British Journal of Nutrition, 65: 271 (1991)
Several strategies have been proposed to reduce the prevalence of iron deficiency in school-age children. Although iron supplements are effective, logistics and compliance are major problems. In addition, the prevalence of iron deficiency is not usually high enough to justify the use of medicinal iron. The iron intake of children can be increased by fortifying a dietary staple such as wheat products or by fortifying a widely consumed food such as sugar, but this can be too costly for developing countries. Hurrell, supra, suggests that the most cost-effective approach to increase iron intake in children is fortification of a specialty food item that is used selectively in this age group. This food item should be appealing to children and ideally should provide other nutritional benefits.
One such item proposed by Hurrell, supra, is chocolate-flavored milk beverages. The consumption of this product is largely limited to school-age children and would not be consumed by adult men who seldom require additional iron. In addition, chocolate-flavored milk would also increase the intake of other minerals and vitamins such as zinc and calcium that are desirable for children.
As noted by Hurrell, supra, there are well-recognized problems associated with fortifying foods and beverages with iron, including chocolate milk drinks. This is particularly true of highly bioavailable iron sources (e.g., ferrous sulfate, ferrous gluconate, etc.) that are commonly used to fortify foods. These irons sources tend to discolor foodstuffs (e.g., by reacting with food components such as anthocyanins, flavanoids and tannins), or are organoleptically unsuitable (e.g., impart a metallic aftertaste). Fortifying foods and, especially, beverages, that contain fats with these iron sources can be very difficult as these materials tend to interact, with the fats typically being oxidized to produce off-flavors. This interaction not only affects the organoleptic and aesthetic properties of the foods and beverages, but also undesirably affects the nutritional bioavailability of these materials. However, the use of inert iron sources (reduced iron, ferric pyrophosphate, etc.) that cause little or no organoleptic problems are poorly absorbed from the gut. The challenge is to fortify foods with highly bioavailable iron sources without adversely affecting the color or taste of the product.
Hurrell, supra, proposes fortifying chocolate drink powders with ferrous fumarate as the iron source. When these ferrous fumarate fortified chocolate drink powders were reconstituted with cold or hot (80.degree. C.) water or milk, the reconstituted beverage was judged acceptable as to color and flavor. However, when these ferrous fumarate fortified chocolate drink powders were reconstituted with boiling water or milk, Hurrell, supra, says the reconstituted beverage "changed color from red/brown to an unacceptable gray." See Id. at page 275. Also, ferrous fumarate imparts a metallic aftertaste that can be undesirable.
Besides iron, there are other important micronutrients that these chocolate drinks could be fortified with. One such micronutrient is iodine. Iodine deficiency is major risk factor for both physical and mental development in a significant number of people. Goiter is the most common manifestation of iodine deficiency. In childhood, iodine deficiency can cause mental retardation, neurological complications such as speech and hearing defects, squint, paralysis, and other physical disorders. While the more severe effects of iodine deficiency are not reversible, they are preventable by appropriate fortification of foods and beverages. See Theme Paper No. 6, "Preventing Specific Micronutrient Deficiencies," INTERNATIONAL CONFERENCE ON NUTRITION.
Another key micronutrient is vitamin A. Vitamin A deficiency is the most common cause of preventable childhood blindness. As a result of insufficient dietary intake and absorption of vitamin A, a significant number of pre-school age children suffer sever forms of eye damage. Vitamin A deficiency can also contribute to decreased physical growth and impaired resistance to infection and lead to increased mortality in children. See Theme Paper No. 6, "Preventing Specific Micronutrient Deficiencies," INTERNATIONAL CONFERENCE ON NUTRITION. Deficiencies in other minerals and vitamins such as vitamin C, B complex vitamins (e.g. thiamine, B6, B12), vitamin D, riboflavin, folic acid, pantothenic acid, vitamin D, vitamin E, zinc, etc., can also cause serious health problems.
Iron fortification of these chocolate drink powders, as well as other foods and beverages, becomes even more of a problem when the drink powder is further fortified with these other minerals and vitamins, especially mineral and vitamin combinations involving, iodine, vitamin A, vitamin C, riboflavin, and folic acid. Even the inclusion of vitamin C alone in chocolate drink powders fortified with ferrous fumarate or ferrous succinate, another highly bioavailable iron source, can cause the development of this undesirable gray color when the powder is reconstituted with aqueous liquids such as water or milk. Iron is a known catalyst that can cause oxidation and decomposition of various vitamins, including vitamins A, thiamine, B6, B12 and vitamin C to name a few. See "Stability Characteristics of Vitamins in Processed Foods," Food Tech., (January 1976), pages 48-54. Iron sources, such as ferrous fumarate and ferrous sulfate, are also known to enhance the sublimation of iodine, thus decreasing the amount of this mineral in the beverage powder.
Accordingly, it would be desirable to provide chocolate drink powders fortified with highly bioavailable iron sources such as ferrous fumarate and ferrous succinate that do not develop an undesirable gray color and metallic aftertaste when reconstituted with aqueous liquids such as water or milk, even when the water or milk has been heated to the boiling point. It would also be desirable to be able to additionally fortify these powders with other key minerals and vitamins without undesirable interactions with the bioavailable iron source.